This invention relates to an appliance for making sorbet or ice cream.
U.S. patent application Ser. No. 292,121 filed Sept. 25, 1972, now U.S. Pat. No. 3,916,637, relates to an electrical domestic appliance intended for making ice cream and fruit sorbet in a cold enclosure, such as the ice box of a refrigerator. Said application is herein incorporated by reference. The principal feature of this apparatus is the provision of means which prevents the stirrer blades from becoming blocked in the ice by effecting progressive withdrawal of those blades from a vertical orientation towards a horizontal orientation under the action of the opposing torque applied to the blades by the hardening of the ice during freezing. The appliance is especially intended for making ice cream and sorbet with two flavours.
U.S. patent application No. 429,820 filed Jan. 2, 1974, now U.S. Pat. No. 3,926,414 relates to a device for automatically stopping the gear motor of the appliance and for indicating when the blades reach their withdrawn position. Said application is herein incorporated by reference. This device is characterised by the fact that one of the stepped pinions of a reducing mechanism, which transmits the rotational movement of the motor to a sprocket driving the blades, is axially displaceable under the action of the reactive torque arising from the resistance offered to the mixer blades by the thickening of the preparation as it freezes.
In one embodiment described in this second patent, a microswitch with two stable positions is used, a moving coil of the microswitch being activated on the one hand by the aforementioned axial displacement and, on the other hand, by the bending of a deformable bimetallic element under the effect of increase in temperature of the magnetic circuit of the motor. The microswitch has to be reset by a push-button extending through the cover of the gear motor housing.
Although working satisfactorily, this embodiment does have certain disadvantages. Thus, a bimetallic strip is difficult to fix either by welding or by screwing due to the structure of the laminar magnetic circuit. In addition, the push-button is difficult to seal.
The object of the present invention is to provide an appliance having an improved automatic stopping device.